SimGrid  3.16
Versatile Simulation of Distributed Systems
/* Copyright (c) 2009-2016. The SimGrid Team. All rights reserved. */
/* This program is free software; you can redistribute it and/or modify it
* under the terms of the license (GNU LGPL) which comes with this package. */
#include "simgrid/msg.h"
#include "xbt/synchro.h"
XBT_LOG_NEW_DEFAULT_CATEGORY(msg_process_migration, "Messages specific for this msg example");
xbt_mutex_t checkpoint = NULL;
xbt_cond_t identification = NULL;
static msg_process_t controlled_process = NULL;
/* The Emigrant process will be moved from host to host. */
static int emigrant(int argc, char *argv[])
XBT_INFO("I'll look for a new job on another machine ('Boivin') where the grass is greener.");
MSG_process_migrate(MSG_process_self(), MSG_host_by_name("Boivin")); /* - First, move to another host by myself */
XBT_INFO("Yeah, found something to do");
msg_task_t task = MSG_task_create("job", 98095000, 0, NULL); /* - Execute some work there */
XBT_INFO("Moving back home after work");
MSG_process_migrate(MSG_process_self(), MSG_host_by_name("Jacquelin")); /* - Move back to original location */
MSG_process_migrate(MSG_process_self(), MSG_host_by_name("Boivin")); /* - Go back to the other host to sleep*/
xbt_mutex_acquire(checkpoint); /* - Get controlled at checkpoint */
controlled_process = MSG_process_self(); /* - and get moved back by the policeman process */
XBT_INFO("I've been moved on this new host: %s", MSG_host_get_name(h));
XBT_INFO("Uh, nothing to do here. Stopping now");
return 0;
/* The policeman check for emigrants and move them back to 'Jacquelin' */
static int policeman(int argc, char *argv[])
XBT_INFO("Wait at the checkpoint."); /* - block on the mutex+condition */
while (controlled_process == NULL) xbt_cond_wait(identification, checkpoint);
MSG_process_migrate(controlled_process, MSG_host_by_name("Jacquelin")); /* - Move an emigrant to Jacquelin */
XBT_INFO("I moved the emigrant");
return 0;
int main(int argc, char *argv[])
MSG_init(&argc, argv);
xbt_assert(argc == 2, "Usage: %s platform_file\n\tExample: %s msg_platform.xml\n", argv[0], argv[0]);
MSG_create_environment(argv[1]); /* - Load the platform description */
/* - Create and deploy the emigrant and policeman processes */
MSG_process_create("emigrant", emigrant, NULL, MSG_get_host_by_name("Jacquelin"));
MSG_process_create("policeman", policeman, NULL, MSG_get_host_by_name("Boivin"));
checkpoint = xbt_mutex_init(); /* - Initiate the mutex and conditions */
identification = xbt_cond_init();
msg_error_t res = MSG_main(); /* - Run the simulation */
XBT_INFO("Simulation time %g", MSG_get_clock());
return res != MSG_OK;